Apparatus and method for marking a surface



R. W. WILSON Feb. 4, 1958 APPARATUS AND METHOD FOR MARKING A SURFACE l Filed July 8, l95 4 2 sheets-sneer 1 INVENTOR Ka m.. kl "Y1-Loge@ ATTORNEY APPARATUS AND METHODFOR A SURFACE Filed July 8. 1954 Feb. 4, 1958 R, w. wlLsoN 2 Sheets- Sheet 2 z k/HEL. (.D- Il-.omas A United States Patent 2,821,890 APPARATUS AND METHOD FOR MARKING A SURFACE Rufus W. Wilson, Huntingdon, Pa., assignmto Wald Industries, Inc., Huntingdon, Pa., a corporation of Pennsylvania Application July 8,1954, Serial No. 442,077

7 Claims. (Cl. 94-44) The present invention relates to surface coating apparatus and to a method of applying a coating to a sur face. More particularly, the present invention relates to a method and apparatus for applying a coating material to surfaces and the like wherein the coating material is intimately mixed with small particles of solid material.

A particular use of 7the present invention is in the application of markers to roads and highways. It is generally recognized in the art of applying road markers, such as center lines and lane margin lines, for example, that the use of reiiecting elements, such as glass spheres, when mixed with a paint binder, is especially effective in promoting safety on the highway, particularly since the glass spheres have auto-collimating characteristics. Due to their auto-collimating characteristics, the small glass spheres are particularly effective in outlining the traffic lanes during night-time driving.

Prior to th-e instant invention, various techniques have been employed in applying the road markers, which generally consist of the paint binder mixed with the small glass spheres, and it has been the usual practice heretofore to apply the road marker in one of several methods. One of the methods employed heretofore was to first apply a paint binder to the road surface by ejecting the paint binder onto the road surface in an atomized mist from a spray gun, the spray gun being attached to a movable vehicle. The small glass spheres were then either dropped or ejected into the wet adhesive paint binder. The glass spheres were normally varied in diameter so that a portion of the spheres would be completely imbedded in the paint binder while a portion would project above the paint binder and thereby provide for immediate illumination. Thus, as the traffic wore down the traffic marking, the larger spheres would be removed by the trafiic shock, but the imbedded spheres would then become visible. Another method employed heretofore in applying the road markers was to premix the paint and the glass spheres and then spray the paint binder and glass sphere mixture onto the road surface to effect thedesired marking. It has been found through' practice that though both of these known techniques have been found to be satisfactory in applying road markers, with the first method the spheres had a tendency to become dislodged due to continued heavy traffic impact and, in the second case, the pre-mixture of the paint and spheres had a tendency to adhere to the spray guns utilized in applying the markers and as a result the spray 111.18 became clogged at frequent intervals. Clogging of the spray guns during the road marking operation necessarily increases the period of time for marking the traffic lanes and necessitates frequent changing and cleaning of the spray guns.

It has also been found that when the glass spheres are premixed with the paint or binder and not applied immediately to the surface to be marked, the spheres which are initially suspended in the paint or binder solution have a tendency to settle with the pigment to the bottom of the premix container, thereby forming a wet concreteice like mass. If the Amass is allowed to remain undisturbed for even a short period of time, it becomes more solid, with the result being that paint lines, valves, strainers and accessory equipment become clogged. If the premixed material is allowed to remain in its container from one striping season to the next and the can is not upended periodcially, the settled materials form a compact mass which is almost impossible to return to the suspended state. Due to these diiculties normally encountered with the premix material, it has become the standard procedure to equip premix striping equipment with an agita tor. If the agitator is air-operated by a portable unit, a relatively large compressor is required to supply the necessary amount of compressed air. If the agitator is mechanically operated, a larger engine is required for the striping machine, to perform the agitating operation in addition to propelling the unit. It is seen, therefore, that by utilizing the agitator with the premix material, the striping equipment is necessarily increased in size and weight.

In order to eliminate the difficulties associated with the premixiug techniques, it has been found desirable to have the paint binder sprayed onto the road surface to effect the desired marker and simultaneously therewith apply the glass spheres from a separate source. In this manner, the spheres would be thoroughly mixed with the paint binder as it is applied to the road and would be sufficiently imbedded in the paint binder to prevent their becoming loosened due to traffic impact.

It is also seen that in other instances where a coating of paint that may be mixed with small particles is applied to a surface, the teaching of the present invention is applicable.

It is therefore an object of the present invention to provide means for applying a coating material to a surface and applying simultaneously therewith a stream of small particles from an independent source.

Still another object of the present invention is to provide road marking apparatus whereby a stream of paint binder is applied to a road surface from an independent source and a stream of small glass spheres is mixed With the stream of paint binder from a second independent source, a mixture of paint binder and glass spheres thereby being formed and defining the finished marking material.

Still another object of the present invention is to teach a method of applying a road marking to a road surface whereby a paint binder and tiny glass spheres are simultaneously directed onto the surface of a road from independent sources.

Still another object of the present invention is to provide means for marking the surface of a road whereby an additional source of glass spheres is adapted to spray an atomized coating of glass spheres onto the freshly applied marker to effect a top or ash coat of spheres, thereby providing for immediate reflectivity of the marker.

Still another object of the present invention is to teach a method of applying a flash coat of spheres onto the top of the marker which has been applied to the surface of the road, the marker containing a paint binder and a multitude of tiny glass spheres.

Other objects and the nature and advantages of the instant invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

Fig. l is a diagrammatic illustration of the apparatus embodied in the present invention;

Fig. 2 is a side elevational view of the apparatus shown in Fig. l illustrating the pattern of the paint binder and particles as they are applied to a surface;

Fig. 3 is a sectional view of the marker as applied by the apparatus embodied in the present invention;

Fig. 4 is a diagrammatic illustration of a modified form -ofthe present invention;v and Fig. 5 is a further modified form of the present invention in which a twin head spray gun is illustrated in partial section.

' Generally, the present invention relates to surface coating apparatus and particularly `-apparatus forl applying a paint to a surface and applying simultaneouslyv therewith a stream of small particles. A preferred application of the present invention is in marking a road surface or the like with trac lines. The road marking apparatus -embodied herein is adapted to be carried by a moving vehicle, generally of the self-propelled type, and includes a spray gun that is located a predetermineddistance fromthe road surface and is adapted to spray' a paint binder thereon to effect a traffic lane stripe. Tiny glass spheres are adapted to be ejected in a continuous stream into the paint binder stream, the sourceof the glass spheres being positioned adjacent the source of' the paint binder. The spheres and paint binder are joined in a common stream and -are then-projected onto the road 'surface to effect the trafic lane marker. A second source for traffic lane marking and includes a nozzle 12 through which an atomized spray of paint binder-mist is-.ejected under the motive force of compressed air. The spray gun and the conventional equipment associated-therewith, such as the compressor and prime mover, are adapted to be mounted on a vehicle preferably of the self-propelled type, the vehicle also carrying a supply of paint-binder and a separate supply of small particles such as glass spheres. The spraygun 10-is connected to the supply of paint binder, the paint binderbeing-.ejectedfrom-the nozzle 12 in a stream 14 onto a surface '-16 to define a marker of predetermined width. The width of the marker is determined by the height of the spray gun -10 from the surface 16 and the angle of the spray fan, as shown more particularly in Fig. 2.

The road or traffic marker as applied by the present invention includes the well known auto-collimating reflecting element, in the present application being shown in the form of tiny glass spheres. The'present invention utilizes two separate and distinct sources Iof the glass spheres, the spheres from each source varying -iny diameter, the purpose of which will be described hereinafter. As shown in Fig. 1, a-spray gun 18 is angularly positioned directly adjacent the spray gun 10 and is located in front of the spray -gun 10 with respectto the direction of travel of the vehicle, the direction of-travel being indicated by the large-arrow shown above thespray gun 10 in Fig. 1. The gun 18 is connected to the source of compressed air and in addition to a supply of the'glass spheres, the compressed air being adapted to eject a stream of the glass spheres indicated at 20 from the spray gun 18 into the paint binder stream 14.

As shown, the stream of tiny glass spheres 20 ejected from the spray gun 18 are intimately mixed with the paint binder stream 14 ejected from the nozzle `12 of the spray gun 10. The glass spheres, which are in` a dry form when they are ejected frornthe spray gun 18, then define with the paint binder stream a marking ma terial 22 for forming a marker 23 for the surface 16 of the road. It'will be seen that as the vehicle carrying the road marking apparatus moves in the direction of the large arrow in Fig. l, the road marker 23'will` be applied as the spheres from the sprayzgun 18 and `the paint binder.14 fron1v the nozzle 12 are expelled onto the surface 16. The dry glass spheres from the spray gun 18 are thoroughly mixed with the paint binder 14 being emitted from the nozzle 12 and form an agglomeration of paint and glass spheres, the cross-section of which is shown in Fig. 3. Since the dry glass spheres ejectedjfrom the spray gun 18 are intimately mixed with the sprayv of'pai'ntbinder, there is little possibility that they will become loos'ened'due to traffic impact when subjectedto traic conditions.

Itlis"desired=finlapplying the road marker 23 that the reflectivity of the marker be produced immediately upon the application thereof. For this purpose, a third spray guni24 yis carried by the 'moving vehicle and is positioned to the "rear'of the spray' gun 10 with respect to the direction of travel of the vehicle. Dry glass spheres indicated at 26 under the force of compressed air are atomized Aand ejected in a fan-like pattern (Fig. 2) from the spray gun'24 onto the surface of the road marker 23 and become imbedded'in the paint binder approximately one-thirdV 'their diameter above the surface thereof. The dry Iglass`spheres"2.6 which are ejected from the spray gun 24 are preferably formed of a larger diameter'th'an those ejected from the spray gun 18. Thus, the larger diameterfspheres 26, which arev applied to the top surface of the'road marker 23, are immediately visible and therefore 'produce instant reflectivity for the road'marker. The rlarger diameter spheres ejected in an atomized fan-shaped pattern from the spray gun are sufciently retained in the top portion of the paint binder by capillary action, whereby the paint binder creeps around the surface of the .spheres to firmly anchor them to the upper portion of the marker, as shown in Fig. 3. The larger spheres 26 are retained'in place until the line is ywornsufficiently by the moving traffic to expose the smaller-'diameter spheres. However, as the larger di- -arnefer spheres are thrown'out of the binder by the moving traffic, the smaller diameter spheres, which are firmly mixed with the paint binder, become visible and thus the reflectivity of the road marker remains effective until the paint binder is finally removed through excessive traffic wear.

Referring now to Fig.'4, a modified form of the invention is illustrated and includes a new type spray gun assembly generally indicated at 30. The spray gun assembly 30Y comprises a conventional spray gun 32 which is connected to a supply of'` paint binder and compressed `air. A suitable nozzle 34 is secured to the spray gun 32 and is adapted to direct an atomized spray 36 from the spray-gun 32 in fan-shaped pattern, as described above in connection with Figs. 1-3. Secured to the lower portion of the spray gun 32 and 'depending downwardly therefrom is a substantially tubular shroud 38. The tubular shroud 38 may be formed in a circular cross section or, if desired, it may be square in cross section or formed inl any other configuration that can be practically utilized. Thei lower edge of Atheshroud 38 is spaced substantially from the-nozzle 34 and is adapted to restrict the fan-shaped pattern of the atomized paint binder spray to a predetermined width. Thus, it is seen that the width of the line or markerfto be applied to a surface indicated at V40 may be varied by vertically adjusting the lower edge of the-shroud with respect tol `the -surface 40. As described above in connection with the surface marking apparatus illustrated in Figs. l and 2, the modified form of the invention shown in Fig. 4 includes a sphere dispensing spray gun 42 thatfis connected to a source of supply of the' glass spheres to be mixed with the paint binder. In order to provide for the introduction ofthe glass spheres'into the paint binder stream 36, the shroud 38 has integrally -formedl thereon a -tubular arm 44 which is adapted-to' receive-l therein a nozzle 46 of the spray gun 42. The spray gun 42 is also connected to the compressed "air source,-and'theifglass lspheres are'thus lejected in a stream 48 into` thepaint binderatornized stream 36. The

`'agglomration of paint binder and spheres is then sprayed in' a fan-shaped pattern from the shroud 38being restricted in width by the lower edge of the shroud, and forms a marker indicated at 50 on the surface 40. Since the spheres are imbedded beneath the surface of the paint binder, the auto-collimating characteristics thereof are not apparent immediately after application of the marker 50 by the marking apparatus 30. In order to render the marker 50 immediately rellective after application thereof, a spray gun 52 is provided and is adapted to spray an atomized stream 54 of relatively large spheres into the surface of the marker 50. As described above, the stream of spheres is partially imbedded in the paint binder form ing the marker 50 and is sufficiently exposed to provide immediate reflectivity for the marker.

It is seen that the marking aparatus 30 including the spray gun 32, shroud 38 and spray gun 42 may be ernployed for coating surface for purposes other than reflective markers. For example, it is contemplated that the apparatus may be utilized to coat a greasy surface with a paint and simultaneously apply to the surface a fine sand or grit. It is also apparent that similar coatings of various types of paints and particles may be sin1ultaneous ly applied to surfaces, whenever it is desirable, by utilizing the apparatus and method described herein.

Referring now to Fig. 5, a further modified form ofl the present invention is illustrated and comprises a spray gun which is generally indicated at 60 and which is provided with means for receiving in a common mixing chamber both the paint binder and the particles to be mixed therewith. The spray gun 60 includes a nozzle 62 which is integrally joined to a mixing chamber 64, the mixing chamber receiving paint binder under pressure from an inlet 66 and small dry particles, such as glass spheres, under pressure from an inlet 68. The

inlets 66 and 68 are suitably connected to a supply of paint binder and spheres, respectively, and are intercon nected to the mixing chamber 64 byr ports 69. In order to control the admission of the paint binder and dry glass spheres through ports 69, control rods 70 are positioned in the ports 69 and are adapted to be actuated by a control arm 72, the control arm 72 being operatively connected to an air operated diaphragm 74. The diaphragm 74 is biased by a spring 76 and is responsive to compressed air admitted through an inlet port 78. An additional port 80 is provided in the body of the spray gun 60 and communicates with the ymixing chamber 64 for the purpose of supplying compressed air for'atomizing, mixing and ejecting the paint binder and spheres.

In operation, the paint binder or coating material is admitted under pressure through the inlet 66 and the dry glass spheres or any suitable particles are admitted under pressure through the inlet 68. The rods 70 are controlled by the diaphragm 74 which is responsive to air admitted through port 78 to admit the paint binder and spheres into the mixing chamber 64. Air under pressure is introduced into the mixing chamber 64 from the port 80 and is adapted to thoroughly mix the paint binder and spheres and then eject the mixture in an atomized stream 82 onto the surface to be marked. It is seen that the spray gun 60 mixes the paint and spheres internally in the mixing chamber and ejects the mixture in the atomized stream 82, as contrasted with the spray guns described above, wherein the paint binder and spheres are mixed externally before being applied to the surface to be marked.

Referring again to Fig. 5, a second spray gun 84 is provided and is adapted to follow the spray gun 60 ejecting an atomized stream of particles 86, onto the coated surface, as described above in connection with Figs. 1-2 and 4. The spray gun 84 thus provides means for applying a ilash coat of the particles or spheres to the coated surface or marker, the particles or spheres being immediately visible after application thereof.

From the foregoing, it is seen that by utilizing the apparatus and method described herein, a surface may be coatedwith a paint material completely mixed with particles in a relatively short period ofvtime. Although the present invention discloses spray guns applying the coating in a fan-shaped pattern of restricted Width, it is considered within the scope of the invention to utilize any type of spraying equipment wherein a motive fluid is adapted to eject the particles into the stream of the coating material, the mixture then being applied to a surface.

The present invention has particular application with road marking equipment and for applying tratc lines on road surfaces. From the description of the apparatus and method set forth above, it will be seen that a road marker for marking tralic lane-s on the surface of a road is quickly and simply applied by the present invention. The auto-collimating elect produced by employing small glass spheres with the paint binder is achieved by ejecting the spheres directly into the paint stream as it is applied to the road surface. The spheres are thus firmly imbedded into the paint binder and as traic wears away the surface of the road marker, the spheres will be constantly visible. In the initial application of the road marker, a. flash coat of the spheres is applied on the top sur-face of the marker and thereby produces instant reflectivity clearly visible undel all driving conditions.

It will also be understood that the present invention contemplates the premixing of the paint binder and glass spheres but avoids the method of ejecting the paint binder and glass spheres through a common spray gun. Normally, when the spheres are premixed with paint bin-der, a certain amount of agitation is necessary prior to the striping operation. However, since the dry glass spheres are contained in a separate receptacle, the agitation is no longer required. It has further been found that -by utilizing the present invention, the life of the marker is extended and, in addition, a more consistent marker may be applied to the road sur-face.

In accordance with the instant invention, it is further to be understood that the apparatus and method herein described may be used for the purpose of mixing pigment or colored particles with the binder for decorative or other coating purposes in such fashion that pigment or particles which may or may notv be of contrasting colo'r may be mixed with the binder immediately prior to application of the binde-r to the surface to be coated or decorated. For example, a marbleized effect has been obtained by introducing pink calcimine into the atomized paint spray, the resulting decoration being a Afairly good imitation of Italian marble. Not only may this decorative effect be obtained on horizontal surfaces, but it may also be applied vertically to obtain decoration of vertical surfaces. lt is to be understood that for decorative purposes when colored pigments are used, a hand gun of the same design as shown in Fig. 5 would be applicable.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appended claims.

W'hat is claimed is:

1. In a method of applying a marker to a surface, comprising the steps of applying a stream of paint binder to said surface, ejecting a stream of dry glass spheres into said paint binder stream, said dry glass spheres intimately mixing with said paint binder as the impinging streams are applied to said surface, whereby the marker formed has autocollimating characteristics, and ejecting a second stream of dry glass spheres onto the surface of the marker in an atomized fan-shaped spray to apply a coating of autocollimating elements thereon for causing instant reectivity thereof.

2. In a method of applying a marker to a road surface, comprising the steps of applying a stream of paint binder to said road surface from a moving external source, eject- 'ing a continuous stream of vglass spheres into sad paint binder; said'glass jspheres intimately mixing with said paint binder as' theimpinging streams are applied to said road surface, and applying an additional stream of glass spheres onto the surface of the newly applied marker to causesaid marker to have immediate refiectivity.

3( In apparatus for applying a coating to a surface,

first means for ejecting a stream of coating material onto 'said surface, the axis' of said ejecting means being perpendicularto said. surface, second means adjacent said first ejecting means for ejecting a stream of particles into contact with Vsaid coating material for intimate mixing `therewith prior to the application thereof to said surface,

and third ejecting means located rearwardly of said first ejecting means' withrespect to the direction of travel 'thereof, the axis of said third ejecting means intersecting said surface rearwardly of the point of application of themixture 'of'said coating' material and stream of par- KVticlers, whereby a second stream of particles ejected from saidthird ejecting'means is deposited on the surface of said' freshly appliedmixture.

4. 'In apparatus for applying a coating to a surface, a

Vfirst nozzle for applying a continuous stream of coating material under pressure to said surface, the axis ofv said first nozzle being perpendicular to said surface, a second nozzle positioned forwardly of said first nozzle with respect to the direction of travel thereof, the axis of said second'nozzle being inclined with respect to the axis of said first nozzle, said second nozzle being immediately Vadjacent said first nozzle whereby a stream of particles Vejected from said second nozzle intimately mixes'with said coating material ejected from said first nozzle, the

`mixture` of coating material and particles thereafter being vapplied to said surface, and a third nozzle located rearwardly of said first nozzle with respect to the direction of travel"thereof, thelaxis of said third nozzle intersecting said' surface rearwardly of the point of application of the mixture of said coating material and stream of particles, vwhereby a second stream of particles ejected from said third nozzle is deposited on the surface of said `mixture of coating material andrst-named particles.

5. In apparatus 'for applying a coating to a surface, a first 'nozzle'ejecting a continuous stream of coating material underpressuretoward said surface, said first nozzle being perpendicular to said surface, a secondnozzle positioned forwardly of said first nozzle with respect to the direction of travel thereof, said second nozzle 'being'loca'ted .immediately adjacent'said first, nozzle and lin'clind' with respect theretdwhereby a stream of par- `ticles "ejected fromfsaid second nozzle is intermix'ed with said stream of coating material, the mixture of coating material and particles thereafter being applied .to

saidsurface, and a third nozzle located rearwardly of said frst'n'ozzle with respect to the direction of travel thereof, Atheaxis of said third nozzle intersecting said surface rearwardly of the point of application of they mixture of coating material and particles, whereby a stream of particles ejected from said thirdV nozzle is deposited on the coating freshly applied to said surface by said first and second nozzles.

'6. In apparatus for applying a coating to a surface, a first nozzle ejecting a continuous stream of coating material under pressure toward said surface, a second nozzle positioned forwardly of said first nozzle with respect tothe direction ofv travel thereof and being inclined with `respect thereto whereby a stream of particles ejected from of particlesv isv deposited on the surface of said freshly applied mixture.

7. In apparatus as setforth in claim 6, which includes a tubular shroud disposed in coaxial relation around said first nozzle and extending below the lowermost end thereof, said tubular shroud having a tubular arm formed thereon and projecting outwardly therefrom, said second nozzle extending into said tubular arm, the lower portion lof said tubularshroud confining the stream of coating 'material and vparticles Yejected from said second nozzle to a predetermined width `as the mixture is applied to said surface.

References Cited in the le of this patent UNITED STATES PATENTS 1,849,945 'Mobley et al .Mar. l5, 1932 1,881,345 Beatty et al. Oct. 4, v1932 2,330,843 Rodli et al. Oct. 5, 1943 2,756,103 Creswell July 24, 1956 

